This invention relates to photographic cameras and more particularly, it concerns an improved cover plate and erecting linkage assembly for bellows-type collapsible cameras.
Collapsible bellows cameras conventionally incorporate a rearwardly disposed body or film housing in which film is loaded for exposure through a lens supported on the front face of a shutter housing movably connected to the film housing by a collapsible bellows providing a light-tight chamber between such housings. The shutter housing is supported by an erecting linkage in a manner facilitating its movement between a collapsed condition against the film housing and an erect or operative condition in which the lens is properly oriented with the optical axis of the camera and with the plane of the film in the film housing. A protective cover is typically associated with the erecting linkage in a manner to be movable between an opened position when the camera is erected and a closed position over the lens, the shutter housing and bellows, in the collapsed condition of the camera, to protect the lens and other delicate components from damage by impact when the camera is carried and also from foreign materials such as dust and the like.
Because the foldable bellows is essentially non-supporting in a structural sense, the erecting linkage provides a sole supporting structure for maintaining optical orientation of the shutter housing and lens in relation to the film to be exposed. As such, the linkage must function with precision and must exhibit sufficient strength and ruggedness to maintain such precision through repeated camera collapsing and erecting cycles. Additionally, there is a need for an easily releasable and yet positive latching arrangement particularly to retain the linkage in its erected condition as well as to retain the protective cover in a closed position against the film housing while the camera is in a collapsed condition.
While the functional requirements of erecting linkage for collapsible cameras have been met by several designs which have existed in the photographic art for many years, there is need for improvement particularly in the achievement of these functional requirements at reduced materials and manufacturing costs. With respect to materials, current state of the art coupled with the strength and precision requirements of the erecting linkage require the use of metal for linkage components. Accordingly, economy in the linkage components is directed primarily to the use of mass production die-stamping techniques in the formation of the erecting linkage components. However, such camera components as the film housing, the shutter housing and the cover are more readily suited to lower-priced materials such as molded plastics. Thus, an effective camera design from a materials cost standpoint, should maximize the use of lower-cost materials where strength and precision requirements permit.
Ease of assembly without compromise of accuracy is also a goal from the standpoint of overall cost reduction. With respect to ease of assembly, the design of each individual component, regardless of the materials from which it is formed, is critical not only with respect to the ultimate camera function served by each component, but from the standpoint of the manner in which each such component may be assembled in the camera. Assembly costs may be further reduced if the overall design provides a capability for final calibration of the assembled parts. In this latter respect, the precise position of the lens and shutter housing with respect to the film plane of the film housing, when the camera is in an erected or operative position, cannot be compromised in a viable photographic camera design.